If i post something on Ebay, and don't like the bids, could i not except the final bid or/and delete the item?

You can only delete the item 24 hours before the auction ends. Someone got a good deal on your item.

No. That's not how it works. Once you post a no reserve or no starting bid auction you are held under Ebay's rules for selling your item to the highest bidder. You can set a reserve price which sets a secret lowest price you will accept for winning the auction. The bidders won't know what that reserve is until someone bids higher than the reserve. At that point, you are obligated to sell the item for the highest bid. You can set a starting bid price, which is essentially the same as a reserve auction, except everyone knows what your reserve price is. it's listed in the auction as a starting bid. If no one bid's higher than your starting bid, then your item will not sell. If they do bid higher than your starting price you are obligated to sell the item.